Methanesulfonic acid mediated solvent free synthesis of conjugated porous polymer networks

ABSTRACT

The present disclosure relates to synthesis of porous polymer networks and applications of such materials.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of U.S. Provisional PatentApplication No. 62/444,479, filed on Jan. 10, 2017, which isincorporated herein by reference.

FIELD OF THE INVENTION

The present disclosure relates to synthesis of porous polymer networksand applications of such materials.

BACKGROUND OF THE INVENTION

The large-scale production and applications of porous polymer networks(PPNs) confronts two major challenges: On one hand, the commonly usedreactions for PPNs synthesis are sensitive to atmosphere and oftenrequire expensive metal catalysts/reagents, adding undesired risk andcost to the potential mass production. On the other hand, thecross-linked nature of PPNs has prohibited feasible processing of theseinsoluble materials into forms relevant to many practical applications.For example, the processing of PPN into membrane and thin films areessential for their applications in gas/solution ultrafiltration [1, 2]or highly sensitive electrical sensors [3-5]. Therefore, there is anurgent demand on cost effective synthetic method for PPN that allows forsealable production of the materials and feasible solution processing.

SUMMARY OF THE INVENTION

The present disclosure relates to synthesis of porous polymer networksand applications of such materials.

The described features, structures, or characteristics of the inventionmay be combined in any suitable manner in one or more embodiments. Inthe following description, numerous specific details are recited toprovide a thorough understanding of embodiments of the invention. Oneskilled in the relevant art will recognize, however, that the inventionmay be practiced without one or more of the specific details, or withother methods, components, materials, and so forth. In other instances,well-known structures, materials, or operations are not shown ordescribed in detail to avoid obscuring aspects of the invention.

Other objects, advantages, and novel features, and further scope ofapplicability of the present invention will be set forth in part in thedetailed description to follow, taken in conjunction with theaccompanying drawings, and in part will become apparent to those skilledin the art upon examination of the following, or may be learned bypractice of the invention. The objects and advantages of the inventionmay be realized and attained by means of the instrumentalities andcombinations particularly pointed out in the appended claims.

In one embodiment, the invention relates to a method for the preparationof porous polymer network comprising: (a) providing: (i) a plurality ofcompounds comprising at least one acetyl group, said plurality ofcompounds comprising at least one compound type, and (ii) analkylsulfonic acid, and (b) treating said compounds under suchconditions that reaction occurs to produce a porous polymer network. Inone embodiment, said alkylsulfonic acid is methanesulfonic acid. In oneembodiment, said alkylsulfonic acid is selected from the groupconsisting of methanesulfonic acid 3-hydroxypropane-1-sulfonic acid,ethanesulfonic acid, dodecane-1-sulfonic acid, trifluoromethane sulfonicacid. In one embodiment, said method is lacking a toxic acid. In oneembodiment, the reaction does not involve a toxic acid or an acid thatdecomposes at high temperatures. In one embodiment, the method does notemploy a toxic acid or an acid that decomposes at high temperature. Inone embodiment, said method is lacking an acid that decomposes at hightemperatures. In one embodiment, said reaction occurs in open airconditions. In one embodiment, wherein said method further providesadditional elements which become embedded (surrounded, encapsulated,implanted, set, fixed, lodged, rooted, etc.) within the porous polymernetwork after the reaction. In one embodiment, said additional elementscomprise nanotubes. In one embodiment, additional elements are selectedfrom the group consisting of: carbon nanotubes, metal nanowires,dendritic metal micro/nano-particles, carbon nanofibers, redox activemetaloxide nanoparticles (such as MnO₂), graphene, graphene oxide, andreduced graphene oxide. In one embodiment, said method includes, but isnot limed to, more than one compound types comprising at least oneacetyl group. In one embodiment, said method includes only one compoundtype comprising, at least one acetyl group. In one embodiment, saidporous polymer network comprises a conjugated porous polymer network. Inone embodiment, said reaction comprises an aldol triple condensation. Inone embodiment, said compound type is acetophenone. In one embodiment,said compound type is selected from the group consisting of:

In one embodiment, said compound type is selected from the groupconsisting of:In one embodiment, said porous polymer network produced has a specificsurface area of greater than 1000 m²/g with a pore volume of 0.40 cm³/g.In one embodiment, said compound comprising at least one acetyl groupand said acid are in a homogenous solution. In one embodiment, saidconditions comprise beating. In one embodiment, said compounds and acidare reacted in a temperature range between 40-110° C. In one embodiment,said heating comprises heating to a first temperature to produce ahomogenous solution, followed by heating to a second temperature todrive said reaction. In one embodiment, said method further comprisesstep (c) wherein said acid is neutralized by aqueous base. In oneembodiment, said method further comprises step (d) wherein said porouspolymer network is extracted with an organic solvent. In one embodiment,said method further comprises step (e) wherein said porous polymernetwork is purified by flash column chromatography.

In one embodiment, the invention relates to method of fabricating of aporous polymer network comprising: (a) providing: (i) a first reactantcomprising a plurality of compounds comprising at least one acetylgroup, said plurality of compounds comprising at least one compoundtype, and (ii) a second reactant comprising an alkylsulfonic acid, and(b) creating a solution of said reactants, (c) casting said solution ina form, and (d) treating said solution under such conditions so as toproduce a porous polymer network. In one embodiment, the casting of step(c) comprises: i) deposition of portion of said solution upon said firstglass substrate, and ii) application of said second glass substrate uponsaid first glass substrate such that the solution is between saidsubstrates. In one embodiment, the treating of step (d) comprises: i)heating said substrates under such conditions to produce a porouspolymer network film. In one embodiment, said alkylsulfonic acid isselected from the group consisting of methanesulfonic acid3-hydroxypropane1-sulfonic acid, ethanesulfonic acid,dodecane-1-sulfonic acid, trifluoromethane sulfonic acid. In oneembodiment, said alkylsulfonic acid is methanesulfonic acid. In oneembodiment, said method is lacking a toxic acid. In one embodiment, saidmethod is lacking an acid that decomposes at high temperatures. In oneembodiment, the reaction does not involve a toxic acid or an acid thatdecomposes at high temperatures. In one embodiment, the method does notemploy a toxic acid or an add that decomposes at high temperatures. Inone embodiment, said method further provides additional elements withinsaid form which become embedded (surrounded, encapsulated, implanted,set, fixed, lodged, rooted, etc.) within the porous polymer networkafter the reaction. In one embodiment, said additional elements comprisecarbon nanotubes, carbon nanofibers, CdS, CdSe, MoS₂, silver or goldnanowires (these composites allows for higher mechanical strength,optical activity or electrical conductivity, leading to applications inultrafiltration membranes, optical sensors, or electrochemicalsupercapacitors). In one embodiment, additional elements are selectedfrom the group consisting of: carbon nanotubes, metal nanowires,dendritic metal micro/nano-particles, carbon nanofibers, redox activemetaloxide nanoparticles (such as MnO₂), graphene, graphene oxide, andreduced graphene oxide. In one embodiment, said method includes morethan one compound types comprising at least one acetyl group. In oneembodiment, said method includes only one compound type comprising atleast one acetyl group. In one embodiment, said porous polymer networkcomprises a conjugated porous polymer network. In one embodiment, saidreaction comprises an aldol triple condensation. In one embodiment, saidcompound type is acetophenone. In one embodiment, said compound type isselected from the group consisting of:

In one embodiment, said compound type is selected from the groupconsisting of:In one embodiment, said porous polymer network produced has a specificsurface area of greater than 1000 m²/g, with a pore volume of 0.40 Inone embodiment, creating a solution at step b) comprises creating ahomogenous solution of at least one compound type comprising at leastone acetyl group and methanesulfonic acid. In one embodiment, saidconditions of step d) comprise heating. In one embodiment, saidcompounds and acid are reacted in a temperature range between 40-110° C.In one embodiment, said heating comprises heating to a first temperatureto produce a homogenous solution, followed by heating to a secondtemperature to drive said reaction. In one embodiment, said methodfurther comprises step (e) wherein said acid is neutralized by aqueousbase. In one embodiment, said reaction occurs in open air conditions. Inone embodiment, said porous polymer network produced has a basicstructure selected from the group consisting of

In one embodiment, said porous polymer network comprises a metalabsorbing porous polymer network.

In one embodiment, the invention relates to a mixture comprising asolution of an alkylsulfonic acid and at least one compound typecomprising one or more acetyl groups. In one embodiment, said solutionis in a cast or mold. In one embodiment, said alkylsulfonic acid isselected from the group consisting of methanesulfonic acid3-hydroxypropane-1-sulfonic acid, ethanesulfonic acid,dodecane-1-sulfonic acid, trifluoromethane sulfonic acid. In oneembodiment, said alkylsulfonic acid is methanesulfonic acid. In oneembodiment, said compound type is acetophenone. In one embodiment, saidcompound type is selected from the group consisting of:

In one embodiment, said compound type is selected from the groupconsisting of:said porous polymer network produced has a basic structure selected fromthe group consisting of

In one embodiment, said porous polymer network comprises a metalabsorbing porous polymer network.

In one embodiment, the invention relates to a porous polymer networkwhich has a basic structure selected from the group consisting of

In one embodiment, said porous polymer network comprises a metalabsorbing porous polymer network.

In one embodiment, the invention relates to a method for nanofiltrationusing a porous polymer network. In one embodiment, said porous polymernetwork comprises a membrane. In one embodiment, said porous polymernetwork comprises a filter. In one embodiment, said nanofiltrationcomprises heavy metal water filtration. In one embodiment, said heavymetal water filtration comprises water purification for pharmaceuticalapplications. In one embodiment, said heavy metal water filtrationcomprises soil remediation. In one embodiment, said heavy metal waterfiltration comprises ground water remediation. In one embodiment, saidnanofiltration comprises size exclusion filtration. In one embodiment,said size exclusion filtration comprises chemical mixture separation. Inone embodiment, said chemical mixture separation comprises filtration ofheavy metals. In one embodiment, said chemical mixture separationcomprises dye exclusion. In one embodiment, said chemical mixtureseparation comprises non-sensitive permeability to nonpolar, polarprotic, and polar aprotic solvents, wherein the permeance of solventsdepends only on the solvent viscosity. In one embodiment, said porouspolymer network which has a basic structure selected from the groupconsisting of

In one embodiment, said porous polymer network comprises a metalabsorbing porous polymer network. In one embodiment, said porous polymernetwork comprising is prepared by a method: (a) providing: (i) aplurality of compounds comprising at least one acetyl group, saidplurality of compounds comprising at least one compound type, and (ii)an alkylsulfonic acid, and (b) treating said compounds under suchconditions that reaction occurs to produce a porous polymer network. Inone embodiment, said alkylsulfonic acid is methanesulfonic acid. In oneembodiment, said alkylsulfonic acid is selected from the groupconsisting of methanesulfonic acid 3-hydroxypropane-1-sulfonic acid,ethanesulfonic acid, dodecane-1-sulfonic acid, trifluoromethane sulfonicacid. In one embodiment, said method is lacking a toxic acid. In oneembodiment, the reaction does not involve a toxic acid or an acid thatdecomposes at high temperatures. In one embodiment, the method does notemploy a toxic acid or an acid that decomposes at high temperature. Inone embodiment, said method is lacking an acid that decomposes at hightemperatures. In one embodiment, said reaction occurs in open airconditions. In one embodiment, wherein said method further providesadditional elements which become embedded (surrounded, encapsulated,implanted, set, fixed, lodged, rooted, etc.) within the porous polymernetwork after the reaction. In one embodiment, said additional elementscomprise nanotubes. In one embodiment, additional elements are selectedfrom the group consisting of: carbon nanotubes, metal nanowires,dendritic metal micro/nano-particles, carbon nanofibers, redox activemetaloxide nanoparticles (such as MnO₂), graphene, graphene oxide, andreduced graphene oxide. In one embodiment, said method includes, but isnot limed to, more than one compound types comprising at least oneacetyl group. In one embodiment, said method includes only one compoundtype comprising at least one acetyl group. In one embodiment, saidporous polymer network comprises a conjugated porous polymer network. Inone embodiment, said reaction comprises an aldol triple condensation. Inone embodiment, said compound type is acetophenone. In one embodiment,said compound type is selected from the group consisting of:

In one embodiment, said compound type is selected from the groupconsisting of:

In one embodiment, said porous polymer network produced has a specificsurface area of greater than 1000 m²/g with a pore volume of 0.40 cm³/g.

DEFINITIONS

To facilitate the understanding of this invention, a number of terms aredefined below. Terms defined herein have meanings as commonly understoodby a person of ordinary skill in the areas relevant to the presentinvention. Terms such as “a”, “an” and “the” are not intended to referto only a singular entity, but include the general class of which aspecific example may be used for illustration. The terminology herein isused to describe specific embodiments of the invention, but their usagedoes not delimit the invention, except as outlined in the claims.

As used in this document, the singular forms “a,” “an,” and “the”include plural references unless the context clearly dictates otherwise.Unless defined otherwise, all technical and scientific terms used hereinhave the same meanings as commonly understood by one of ordinary skillin the art. Nothing in this disclosure is to be construed as anadmission that the embodiments described in this disclosure are notentitled to antedate such disclosure by virtue of prior invention. Asused in this document, the term “comprising” means “including, but notlimited to.”

As used herein, the term “solvent” as used herein describes a liquidthat serves as the medium for a reaction or a medium for thedistribution of components of different phases or extraction ofcomponents into said solvent.

As used herein, the term “polar solvent” as used herein describessolvents that have large dipole moments (aka “partial charges”); theyoften contain bonds between atoms with very differentelectronegativities, such as oxygen and hydrogen. Non-limiting examplesof polar solvents include polar aprotic solvents and polar proticsolvents. Non-limiting examples of polar protic solvents include but arenot limited to: formic acid, n-butanol, isopropanol, n-propanol,ethanol, methanol, acetic acid, and water. Non-limiting examples ofpolar aprotic solvents include but are not limited to: tetrahydrofuran,ethyl acetate, acetone, dimethylformamide, acetonitrile, dimethylsulfoxide, nitromethane, and propylene carbonate.

As used herein, the term “miscibility” as used herein describes theproperty of substances to mix in all proportions, forming a homogeneoussolution. The term is most often applied to liquids, but applies also tosolids and gases. Water and ethanol, for example, are miscible becausethey mix in all proportions.

As used herein, the term “water miscible solvent” as used hereindescribes solvents that are able to form a homogeneous solution withwater. Examples of water miscible solvents include, but are not limitedto: acetic acid, acetone, acetonitrile, dimethylformamide, dimethylsulfoxide, dioxane, ethanol, methanol, n-propanol, isopropanol, andtetrahydrofuran.

As used herein, the term “non-polar solvent” as used herein describessolvents contain bonds between atoms with similar electronegativities,such as carbon and hydrogen (for example hydrocarbons, such asgasoline). Nonlimiting examples of non-polar solvents include, but arenot limited to: pentane, cyclopentane, hexane, cyclohexane, benzene,toluene, 1,4-dioxane, chloroform, diethyl ether, and dichloromethane.

As used herein, the term “water immiscible solvents” as used hereindescribes solvents that are not able to form a homogeneous solution withwater. Examples of water immiscible solvents include, but are notlimited to: benzene, n-butanol, butyl acetate, carbon tetrachloride,chloroform, cyclohexane, 1,2-dichloroethane, ethyl acetate, di-ethylether, heptanes, hexane, methyl-t-butyl ether, methyl ethyl ketone,pentane, petroleum ethers, di-isopopyl ether, trichloroethylene andxylene.

As used herein, the term “acetyl group” is used throughout thespecification to describe a functional group, the acyl with chemicalformula (CH₃CO—) and the structure:

The acetyl group contains a methyl group single-bonded to a carbonyl.The carbonyl center of an acyl radical has one nonbonded electron withwhich it forms a chemical bond to the remainder R of the molecule,

As used herein, the term “aldol condensation” is used throughout thespecification to describe a condensation reaction in organic chemistryin which an enol or an enolate ion reacts with a carbonyl compound toform a β-hydroxyaldehyde or β-hydroxyketone, followed by dehydration togive a conjugated enone.

As used herein, the term “methanesulfonic acid” or “MSA” is usedthroughout the specification to describe a colorless liquid with thechemical formula CH₃SO₃H and the structure

As used herein, the term “conjugated porous polymer network” is usedthroughout the specification to describe a

As used herein, the term “conjugated microporous polymer” is usedthroughout the specification to describe a sub-class of porous materialsthat are related to structures such as zeolites, metal-organicframeworks, and covalent organic frameworks, but are amorphous innature, rather than crystalline. CMPs are also a sub-class of conjugatedpolymers and possess many of the same properties such as conductivity,mechanical rigidity, and insolubility. CMPs are created through thelinking of building blocks in a π-conjugated fashion and possess 3-Dnetworks [6].

As used herein, the term “acetophenone” is used throughout thespecification to describe the organic compound with the formulaC₆H₅C(O)CH₃ (also represented by the letters PhAc or BzMe), is thesimplest aromatic ketene.

As used herein, the term “1,1′-(1,4-phenylene)diethanone” is usedthroughout the specification to describe an organic compound with thestructure

As used herein, the term “1,1′-(oxybis(4,1-phenylene))diethanone” isused throughout the specification to describe an organic compound withthe structure

As used herein, the term“(S)-1,1′-(9,9′-spirobi[fluorene]-7,7′-diyl)diethanone” is usedthroughout the specification to describe an organic compound with thestructure

As used herein, the term“1,1′,1″-(nitrilotris(benzene-4,1-diyl))triethanone” is used throughoutthe specification to describe an organic compound with the structure

As used herein, the term “specific surface area” is used throughout thespecification to describe a property of solids defined as the totalsurface area of a material per unit of mass, (with units of m²/kg orm²/g) or solid or bulk volume (units of m²/m³ or m^(˜1)).

As used herein, the term “pore volume” is used throughout thespecification to describe a the ratio of a porous material's air volumeto a porous materials total volume.

As used herein, the term “porosity” or “void fraction” is usedthroughout the specification to describe a measure of the void (i.e.“empty”) spaces in a material, and is a fraction of the volume of voidsover the total volume, between 0 and 1, or as a percentage between 0 and100%,

As used herein, the term “homogenous solution” is used throughout thespecification to describe a mixture of two or more components that havea uniform appearance and composition.

As used herein, the term “open air” is used throughout the specificationto describe a condition under which an reaction occurs without specialprecautions made to provided a closed atmosphere. Under theseconditions, the reaction is subject to the surrounding air pressure andhumidity.

As used herein, the term “alkylsulfonic acid” is used throughout thespecification to describe a member of the class of organosulfurcompounds with the general formula R—S(═O)₂—OH, where R is an organicalkyl and the S(═O)₂—OH group a sulfonyl hydroxide.

As used herein, the term “toxic acid” is used throughout thespecification to describe acids that are classified in Category 1-3according to GHS Classification in accordance to 29 CFR 1910.

As used herein, the term “nanofiltration” or “NF” is used throughout arelatively recent membrane filtration process used most often with lowtotal dissolved solids water such as surface water and freshgroundwater, with the purpose of softening (polyvalent cation removal)and removal of disinfection by-product precursors such as naturalorganic matter and synthetic organic matter.

DESCRIPTION OF THE FIGURES

The accompanying figures, which are incorporated into and form a part ofthe specification, illustrate several embodiments of the presentinvention and, together with the description, serve to explain theprinciples of the invention. The figures are only for the purpose ofillustrating a preferred embodiment of the invention and are not to beconstrued as limiting the invention.

FIG. 1a shows a model reaction for methanesulfonic acid catalyzed aldoltriple condensation.

FIG. 1b shows the possible reaction mechanism for aldol triplecondensation.

FIG. 1c shows the structure of different monomers (M1-M5) for preparingporous polymer networks (PPN1-PPN5).

FIG. 2a shows methanesulfonic acid catalyzed ATC reaction for PPN1.

FIG. 2b shows the relationship between the reaction temperature and BETsurface area for PPN1.

FIG. 2c shows the 77 K N₂ sorption isotherms.

FIG. 2d shows the pore size distribution of PPN1 at 110 reactiontemperature.

FIG. 3a shows a FT-IR spectroscopy of PPN1 at different reactiontemperatures (100° C., 110° C., 130° C. and 150° C.).

FIG. 3b shows the ¹³C CP/MAS NMR spectra of the PPN1 at 110° C. reactiontemperature recorded at MAS rate of 5 kHz, asterisks (*) indicaterotational sidebands.

FIG. 4a shows a “Casting-followed-by-reaction” strategy to make anorganic porous film.

FIG. 4b shows the MSA solution between two glass substrates.

FIG. 4c shows an organic porous films formed between two glasssubstrates.

FIG. 4d shows free-standing organic porous films in ethanol.

FIG. 4e shows a SEM image of PPN1 film PPN1 film (left, scale bar 1 mm),PPN1 film's surface (middle, scale bar 500 nm), PPN1 film's edge (right,scale bar=20 μm).

FIG. 5 shows photos of reaction process for PPN synthesis, specificallythe color change during the synthesis of PPN1.

FIG. 6 shows a N₂ Absorption Isotherms of PPN2 at 77K.

FIG. 7 shows a N₂ Absorption Isotherms of PPN3 at 77K.

FIG. 8 shows a N₂ Absorption Isotherms of PPN5 at 77K.

FIG. 9 shows a N₂ Absorption Isotherms of PPN1 film at 77K.

FIG. 10 shows a TGA trace of PPN1-PPN5.

FIG. 11a shows fabrication method of PPN film.

FIG. 11b shows PPN1 structure and pore size.

FIG. 11c shows a digital picture of free standing PPN1 film.

FIG. 12 shows a schematic concept of PPN/ carbon nanotube compositesdevice. Potential applications can be expected in: ultrafiltrationmembranes, gas sensors, supercapacitors. All of these applications relyon high porosity integrated with high mechanical strength(ultrafiltration membrane), or high porosity with high electricalconductivity (gas sensor and supercapacitor). In one embodiment, otherelements to be casted with PPN include, but is not limited to, metalnanowires, dendritic metal micro/nano-particles, carbon nanofibers,redox active metaloxide nanoparticles (MnO₂), graphene, graphene oxide,and reduced graphene oxide.

FIG. 13 shows the structure of two particular porous polymer networks.It is believed that these particular porous polymer networks may beuseful in the industrial application of metal removal.

FIG. 14 shows one embodiment of a nanofiltration setup of PPN films.

FIG. 15 a-c shows the selective dye adsorption of dyes into PPN1.

FIG. 16 shows the rejection rate of PPN1 film against organic dyes withdifferent molecular weights: rhodamine B 480 g/mol, bromothymol blue 624g/mol, brilliant blue 826 g/mol, rose bengal 1017 g/mol indicating amolecular weight cutoff for dye adsorption.

FIG. 17 shows dye rejection by PPN1 film of dyes Rose Bengal andBrilliant Blue R.

FIG. 18 shows the UV-vis absorption spectra of bromothymol blue feedsolution, the permeate solution, and the retentate solution.

FIG. 19 shows the permeance of different solvents through PPN1 film.

FIG. 20 shows the PPN1/CFP composites process

FIG. 21 shows weight percentage versus loading times for CH loaded withPPN.

FIG. 22 shows the quantity adsorbed versus relative pressure for PPN1adsorbtion and desorption.

FIG. 23 shows the morphology of PPN1/CFP with loading 4 times with PPN1at 100 μm resolution.

FIG. 24 shows the morphology of PPN1/CFP with loading 4 times with PPN1at 50 μm resolution and 20 μm resolutions, respectively.

FIG. 25 shows a morphology study of various PPN films.

FIG. 26 shows thickness control of PPN films PPN1 and PPN6 on glass.

DETAILED DESCRIPTION OF THE INVENTION

The present disclosure relates to synthesis of porous polymer networksand applications of such materials.

It will be readily understood that the components of the embodiments asgenerally described herein and illustrated in the appended figures couldbe arranged and designed in a wide variety of different configurations.Thus, the following more detailed description of various embodiments, asrepresented in the figures, is not intended to limit the scope of thepresent disclosure, but is merely representative of various embodiments.While the various aspects of the embodiments are presented in drawings,the drawings are not necessarily drawn to scale unless specificallyindicated.

The present invention may be embodied in other specific forms withoutdeparting from its spirit or essential characteristics. The describedembodiments are to be considered in all respects only as illustrativeand not restrictive. The scope of the invention is, therefore, indicatedby the appended claims rather than by this detailed description. Allchanges which come within the meaning and range of equivalency of theclaims are to be embraced within their scope.

Reference throughout this specification to features, advantages, orsimilar language does not imply that all of the features and advantagesthat may be realized with the present invention should be or are in anysingle embodiment of the invention. Rather, language referring to thefeatures and advantages is understood to mean that a specific feature,advantage, or characteristic described in connection with an embodimentis included in at least one embodiment of the present invention. Thus,discussions of the features and advantages, and similar language,throughout the specification may, but do not necessarily, refer to thesame embodiment.

Furthermore, the described features, advantages and characteristics ofthe invention may be combined in any suitable manner in one or moreembodiments. One skilled in the relevant art will recognize, in light ofthe description herein, that the invention can be practiced without oneor more of the specific features or advantages of a particularembodiment. In other instances, additional features and advantages maybe recognized in certain embodiments that may not be present in allembodiments of the invention.

Reference throughout this specification to “one embodiment”, “anembodiment”, or similar language means that a particular feature,structure, or characteristic described in connection with the indicatedembodiment is included in at least one embodiment of the presentinvention. Thus, the phrases “in one embodiment”, “in an embodiment”,and similar language throughout this specification may, but do notnecessarily, all refer to the same embodiment.

In one embodiment, the invention relates to a method for the preparationof conjugated porous polymer network under ambient condition comprising:(a) providing: (1) at least one compound comprising at least one acetylgroup, and (ii) methanesulfonic acid, and (b) treating said compoundsunder such conditions that an aldol triple condensation occurs toproduce a conjugated porous polymer network. In one embodiment, saidcompound comprising at least one acetyl group is acetophenone. In oneembodiment, said compound comprising at least one acetyl group isselected from the group consisting of:

In one embodiment, said porous polymer network produced has a basicstructure selected from the group consisting of

In one embodiment, said porous polymer network comprises a metalabsorbing porous polymer network. In one embodiment, said conjugatedporous polymer network produced has a specific surface area of greaterthan 1000 m²/g, with a pore volume of 0.40 cm³/g. In one embodiment,said conditions comprises creating a homogenous solution of at least onecompound comprising at least one acetyl group and methanesulfonic acid.In one embodiment, said conditions comprises heating. In one embodiment,said method further comprises step (c) wherein said acid is neutralizedby aqueous base, in one embodiment, said method further comprises step(d) wherein said conjugated porous polymer network is extracted with anorganic solvent. In one embodiment, said method further comprises step(e) wherein said conjugated porous polymer network is purified by flashcolumn chromatography. In one embodiment, said method further comprisesfabrication of a porous polymer network film comprising: providing: afirst glass substrate and a second glass substrate: i) deposition ofportion of said solution upon said first glass substrate, ii)application of said second glass substrate upon said first glasssubstrate with deposited solution, and iii) heating said substratesunder such conditions to produce a porous polymer network film.

INTRODUCTION

This invention provides a new scalable synthetic method for thepreparation of conjugated porous polymer networks (cPPN) throughinexpensive Aldol triple condensation reaction mediated bymethanesulfonic acid (MSA). This process is a highly efficient tandemtransformation that fuses three aromatic acetyl groups into one benzenering. A wide scope of different cPPN were achieved from thecorresponding acetyl functionalized substrates. The unique reactioncondition allows for solution process of the cPPN using a“casting-followed-by-reaction” strategy. This unique and versatilesynthetic approach features mild conditions, low cost, excellentefficiency, and wide substrate scope, affording processed, highly porouscPPNs with controllable pore size distribution and properties.

This low cost, highly efficient, versatile synthetic method may be usedfor the mass production of cPPNs, which are useful for gas storage, gasseparation, energy storage, catalysis and fabricating electronicdevices. Compared to their non-conjugated counterparts, cPPNs possesshigher thermal and chemical stability, as well as superior chargecarrier conductivity. In addition, porous thin film of these cPPNmaterials can be solution-processed for device fabrication. Commercialproduct of the bulk cPPN materials, and the processed cPPN thin filmswill be developed using this method.

In recent years, microporous materials, such as metal-organic frameworks(MOFs), covalent organic frameworks (COFs), and conjugated porouspolymer networks (cPPNs), draw tremendous industrial attentions becauseof their applications in gas storage, energy storage, catalysis andmolecular separations. Most reported synthetic strategy for cPPNs,however, relies on noble metal-catalyzed cross-coupling reactions, whichare expensive and often leave behind residue metal contamination. Thisinvention uses inexpensive MSA (99% pure <$2,000/metric ton) to mediatethe reaction so that noble metal is not involved in the potential massproduction. The catalyst residue can be readily removed by means ofethanol wash. Moreover, the unique physical property of MSA and the highefficiency of the reaction allows for solution process of the cPPNs intothin films that is ready for advanced device fabrication.

Advantageous Aspect Methanesulfonic acid as an inexpensive yetenvironmentally benign reagent was introduced for the first time inaldol triple condensation reaction to construct cPPNs. In contrast,previously reported aldol triple condensation for porous materialsrequired toxic or unstable reagents, such as silicon tetrachloride,4-methylbenzenesulfonic acid and thionyl chloride, limiting itspractical applications suitable for commercialization. Compare to theseacid catalysis, methanesulfonic acid possess low toxic, mild reactioncondition and easy to handle characteristics. More importantly,methanesulfonic acid is a liquid acid so that it allows for solutionprocessing of the reaction precursors into different forms.

Advantageous Aspect 2: Previously reported methods for cPPNs aresensitive to water or oxygen so that sealed tube or nitrogen protectedvessels are required for those processes. These requirements addundesired risk and cost to mass production of cPPN materials. Thisinvention provides a method that can be performed under ambientcondition (open air) which allows for inexpensive reaction operation.

Advantageous Aspect 3: This invention also enables thin film preparationof cPPNs through a “casting followed-by-reaction”, overcoming thegenerally formidable challenges in processing insoluble polymernetworks. This ability opens the door of incorporating, cPPN thin filmsinto products such as sensors and energy storage devices.

By applying the synthetic strategy, we are planning to functionalize thestarting materials with different functional groups. The correspondingconjugated porous polymer networks will be employed in gas adsorption,device processing and lithium-ion battery application.

In one embodiment, the invention relates to a highly efficient, aldoltriple condensation method for scalable synthesis of conjugated porouspolymer networks. It is believed that this strategy features low cost,simple starting material and reagent, as well as feasible operation,ideal for mass production of bottom-up synthesized organic porousmaterials. In addition, this method enables solution processing ofporous polymer materials through a “casting-followed-by-reaction”strategy into desired forms that are essential for practicalapplications.

Bottom-up synthesized microporous materials, such as metal organicframeworks NM) [7, 8], covalent organic[9] frameworks (COFs) [9, 10] andporous polymer networks (PPNs) [6, 11-13], demonstrates promisingpotential applications in gas storage [14], catalysis [15, 16] andmolecular separations [8, 17], etc. Among them, PPNs are non-crystallinematerials constructed by irreversible reactions, such as Suzuki [18,19], Sonogashira [20, 21], and Yamamoto coupling [12]. The resultingrigid yet conjugated connections endow high porosity and extraordinarystability to PPNs. In contrast, highly crystalline MOFs and COFs areless robust in harsh conditions because of the reversible and dynamicbond formation during their synthesis [22, 23]. Therefore, PPNs areconsidered an appropriate candidate material for processes andoperations under harsh conditions. The large-scale production andapplications of PPNs, however, confronts two major challenges: On onehand, the commonly used reactions for PPNs synthesis are sensitive toatmosphere and often require expensive metal catalysts/reagents, addingundesired risk and cost to the potential mass production. On the otherhand, the cross-linked nature of PPNs prohibited feasible processing ofthese insoluble materials into forms relevant to many practicalapplications. For example, the processing of PPN into membrane and thinfilms are essential for their applications in gas/solutionultrafiltration [1, 2] or highly sensitive electrical sensors [3-5].

Under such circumstances, there is an urgent demand on cost effectivesynthetic method for PPN that allows for scalable production of thematerials and feasible solution processing. In order to achieve thisgoal, several design principles should be followed. First, the backbonestructure of porous materials should be rigid and composed of aromaticsp² building blocks. The rigid backbone constitution can support thepersistent porous architecture while the sp² conjugation leads to highchemical and thermal stability. Second, the starting materials,reagents/catalysts and solvents should be low cost and environmentallybenign and the reaction should not sensitive to moisture and air. Lastbut not least, liquid-phase reaction with minimized number ofreagents/catalysts is preferred, so that the liquid reaction mixturecould be used as precursor for solution-processing. Herein, amethanesulfonic acid (MSA) mediated aldol triple condensation reactionthat addresses these challenges simultaneously is described. This methodoffers a green strategy for the mass production of highly stable PPNmeanwhile enables solution-phase processing of these materials intouniform films and potential composite membranes for advancedapplications.

Aldol condensation is an effective reaction to construct carbon-carbonbonds and widely used in organic synthesis [24]. In 1991, Elmosy et atreported a tandem aldol triple condensation (ATC) reaction thatconstructs a central benzene ring from aromatic acetyl groups [25]. Inthe presence of acid, this reaction involves two aldol condensationsteps following by a [3+3] electrocyclic reaction and aromatization(FIG. 1a ). Due to its highly efficient nature and the intriguing C3symmetry of the products, ATC reaction has been widely used in thesynthesis of star-shaped molecules [26] and dendrimers [27]. Recently,several groups also reported the preparation of organic microporousmaterials by using ATC reaction [28-30]. In these reactions, however,either toxic and irritate acid was used as catalysis, or the acids wereeasily decomposed at high temperature. Furthermore, all these methodsrequired specialized reactors to protect the reaction from oxygen andmoisture. Therefore, large-scale application of ATC reaction for PPNssynthesis was limited, not to mention feasible solution processing ofPPNs.

One embodiment of the present invention envisioned that MSA could be anideal acid for the ATC synthesis of PPN. Compared to the widely-exploredacidic reagents for ATC reaction (such as silicon tetrachloride [25],4-methylbenzenesulfonic acid [28, 30], sulfuric acid and thionylchloride [29]), MSA is non-toxic, environmentally benign and stable athigh temperature [31, 32]. More importantly, MSA is a liquid acid sothat it can serve not only as the catalyst but also as the solvent inreaction. As shown in a model reaction (FIG. 1b ) on acetophenone, 0.2eq MSA was the only reagent used for the reaction without additionalsolvent. After 12 hours at 130° C. the product 1, 3, 5-triphenylbenzenewas isolated in 86% yield. Compared to previously reported ACT reactionsand metal catalyzed cross-coupling reactions commonly used for PPNsynthesis, this method is easy to handle, free of solvent, andenvironmentally benign, while still maintaining a high efficiency. Inthis context, aromatic starting materials (M1 to M5) functionalized withmultiple acetyl groups were prepared in order to synthesize thecorresponding PPNs by using this promising MSA catalyzed ACT method (seeExample 1-Example 3).

RESULT AND DISCUSSION

1, 4-diacetlybenzene (M1) was firstly carried out as model reaction toevaluate this method, M1 was suspended in an excess amount of MSA (10eq) in a small vial. After heating for several minutes, M1 was fullydissolved in MSA. At the same time, the color of the solution wasgradually turned from yellow to orange (FIG. 5), suggesting theformation of a highly conjugated π-system during the ATC reaction. Afterheating for 12 hours, a deep red conjugated microporous polymer (PPN1)was obtained by washing with ethanol in quantitative yield. An openglass vials were used as the reactor and no extra protective equipmentwere needed, demonstrating that the reaction is not sensitive to ambientoxygen or moisture. This feature can decrease the cost to prepareorganic porous materials significantly.

Nitrogen adsorption-desorption isotherm measurements were employed toanalyze the porosity of PPN1. Brunauer-Emmet-Teller (BET) surface areawas used as the parameter to optimize the reaction condition for highlyporous products. The reactions were performed under differenttemperatures ranging from 100 to 150° C. When reaction temperatureincreased from 100 to 110° C., the BET surface area of PPN1 wasincreased (FIG. 2b ). Higher temperature can increase the reaction rateand the solubility of polymeric intermediates in MSA, so higher reactionconversion was expected to increase the porosity and BET surface.However, the BET surface of PPN1 started to decrease monotonously whentemperature increased from 110° C. to 150° C. This observation wasattributed to the over-fast reaction rate at a higher temperature, themicroporous network grew too quickly so that more defects were formed togive a lower BET surface. The optimized BET surface area of PPN1 was1054 m²/g, which was obtained from the reaction at 110° C. (FIG. 2c ).This value represents the highest BET surface area obtained in ATCsynthesized PPNs [28, 29, 33]. The pore size distribution of this samplewas measured by nitrogen adsorption-desorption isotherm at 77K (FIG. 2d). Majority of the pore sizes were less than 10 nm and are mainly in therange of 1˜2 nm. This result agrees with the diameter of smallestrepeating cyclic structure in the polymer networks while considering thekinetically trapped larger defect pores.

The PPN1 structure was also investigated by FT-IR spectroscopy. As shownin FIG. 3a , there are two peaks around 1700 cm⁻¹). For corresponding tocarbonyl stretching of unreacted acetyl group (1718 cm⁻¹) and α,β-unsaturated ketone (1683 cm⁻¹). For the PPN1 formed at a lowertemperature (100° C.), the strong peak associated with acetyl groupsindicated that a large fraction of the acetyl groups were unreacted dueto the relative low reaction temperature. When the temperature wasincreased, the peak of acetyl group was weakened significantly and theintensity of the α, β-unsaturated ketone peak was increased. For thePPNs formed at temperatures higher than 100° C., the relative intensityof the benzene, stretching peak (1507 cm⁻¹) compared to α, β-unsaturatedketone (1683 cm⁻¹) was firstly increased from 100° C. to 110° C. thendecreased from 110° C. to 150° C. This result agreed with the conclusionmade from the BET surface area measurements (FIG. 2b ). Furtherstructure elucidation of PPN1 was performed by using solid-state ¹³CCP/MAS NMR spectroscopy (FIG. 3b ). Two major signals at chemical shiftof 138.7 and 124.1 ppm were identified as the aromatic carbon with oneproton (un-substituted benzene carbon) and without proton (substitutedbenzene carbon). This result agreed with the proposed PPN1 structure asshown in FIG. 3a . Due to the low sensitivity of this method, however,the expected peaks corresponding to defects, such as acetyl group and α,β-unsaturated ketone, were not found. In addition, elementary analysis(Table 1) result demonstrated that there was still oxygen in PPN1,corresponding to these defects.

TABLE 1 Results of the elemental analysis C(%) H(%) N(%) O(%) PPN1(experiment) 84.64 4.95 N/A 10.41^(a) PPN1 (theoretical) 95.21 4.79 0 0PPN2 (experiment) 79.91 5.14 N/A 14.95^(a) PPN2 (theoretical) 88.05 4.620 7.33 PPN3 (experiment) 71.23 4.92 N/A N/A PPN3 (theoretical) 71.854.31 0 0 PPN4 (experiment) 85.70 4.78 N/A 9.52^(a) PPN4 (theoretical)95.57 4.43 0 0 PPN5 (experiment) 81.55 4.98 3.98 9.49^(a) PPN5(theoretical) 90.82 4.76 4.41 0 ^(a)Estimated from C, H and N atoms.

TABLE 2 Porosity of Microporous Polymer PPN1 to PPN5 Microporous S_(BET)V_(micro) V_(total) polymer Monomer (m²/g)^(a) (cm³/g)^(b) (cm³/g)^(c)PPM M1 1054 0.28 0.42 PPN2 M2 515 0.04 0.20 PPN3 M3 699 0.04 0.25 PPN4M4 N/A N/A N/A PPN5 M5 729 0.17 0.31 PPN1 film M1 802 0.14 0.28^(a)Surface area calculated from nitrogen adsorption-desorption isothermat 77K using the BET method. ^(b)Micropore volume calculated fromnitrogen adsorption isotherm using the t-plot method. ^(c)Total porevolume at P/P₀ = 0.97.

PPN2 to PPN5 were synthesized using the optimized reaction condition.The porosity properties were summarized in Table 2, The BET surface areaof PPN2, PPN3 and PPN5 were lower than that of PPN1. This decrease inporosity was attributed to the higher flexibility of M2, M3 and M5compare to M1, and the possibility of network interpenetration due totheir longer length. Interestingly, PPN4 showed very low porosity,likely because of the low reactivity of the acetyl groups on M4 and lowstability of spirofluorene. N₂ absorption isotherms for PPN1, PPN2, PPN3and PPN5at 77K (FIG. 2c , FIG. 6, FIG. 7, FIG. 8, and FIG. 9) showedhigh gas uptake at low relative pressures and a flat course in theintermediate section, which is typical type 1 adsorption-desorptionisotherms. Thermogravimetric analysis (TGA) was performed to measure thethermal stability of PPN1-PPN5 (FIG. 10). PPN3 showed a distinctiveweight loss before 200° because of the lower thermal stability offerrocene unit. Other than PPN3, all other samples demonstrated goodthermal stability with decomposition temperature over 400° C. because ofthe robust nature of their rigid aromatic backbones.

Although organic porous materials have been developed for many years, itis still a formidable challenge to process high quality thin films ormembranes of PPNs or COFs [34, 35]. The rigid cross-linked network ofthese porous materials makes it almost impossible to solubilize or meltthe materials for solution- or melt-processing. In this case, however,this processing problem can be addressed by taking advantage of thefeatures of this MSA mediated ATC reaction: Because MSA serves as thecatalyst and the solvent simultaneously, this unique reaction conditionallows for a simple “casting-followed-by-reaction” strategy to fabricatea film of this organic porous network. MSA solution of M1 was droppedonto a glass substrate with two small pieces of glass as holder (FIG. 4a). Another slide of glass was covered onto the substrate so that the MSAsolution was confined in this mold made of glass slides. This set up washeated to 110° C. for 24 hours to allow the formation of the PPN as athin film. The color changed from orange to deep red (FIG. 4b and FIG.4c ), matching the color change in the bulky solution reaction. Afterremoving the top substrate, the as synthesized organic porous films wereeasily peeled off by treatment of ethanol to obtain a freestanding film(FIG. 4d ). N₂ adsorption-desorption isotherm measurement on this PPN1thin film gave a BET surface area of 802 m²/g, demonstrating excellentporosity of the material synthesized in a thin film state. Underscanning electron microscope (SEM), PPN1 film exhibited a smooth surfaceand uniform thickness. Overall, successful preparation of PPN1 filmsfrom a solution precursor enables future processing of PPN materialsinto various forms

including thin films, fibers, molded shapes, and as composites withsupporting materials, paving the way for practical applications of theseporous materials in separation, filtration, and sensing.

In summary cost effective syntheses of organic microporous polymernetworks are achieved by using methanesulfonic acid (MSA) mediated aldoltriple condensation reaction. A series of porous polymer networks wereobtained in highly yields. This method shows significant feasibilitycompared to previous reported similar methods, on account of the lowtoxic, environmentally benign and stable characters of MSA as well asthe simple reaction setup. Specific surface area of these porousmaterials can reach 1054 m²/g with a pore volume of 0.42 cm³/g. Thesimple composition of the precursor solution in MSA allows for solutionprocessing of porous thin films of these insoluble polymer networksthrough a “casting-followed-by-reaction” strategy. These uniquecharacteristics make this method a promising strategy to mass produceand process functional microporous materials for heterogeneouscatalysis, separation, and gas storage.

EXAMPLES

The following examples are provided in order to demonstrate and furtherillustrate certain preferred embodiments and aspects of the presentinvention and are not to be construed as limiting the scope thereof.

Example 1 Synthesis

1,3,5-triphenylbenzene, Acetophenone (500 mg, 4.17 mmol) andmethanesulfonic acid (80 mg, 0.83 mmol) was added to a 25 mL roundflask. The mixture was stirred at 130° C. for 12 h. It was subsequentlyneutralized by saturated NaHCO₃ and extracted with CH₂Cl₂ (3×20 mL). Thecombined organic layers were dried by MgSO₄, filtered, and concentratedin vacuum. The residue was purified by flash column chromatography(SiO₂, Hexane) to give the product as white solid (364 mg, 1.19 mmol,85.7%).

Example 2

General procedure of PPN synthesis by MSA catalyzed ATC reaction. To a20 mL glass vial with cap, the monomer (1 equivalent) andmethanessulfonic acid (10 to 20 equivalents) was added and pre-heated to40° C. so that a homogenously solution is obtained. The solution wassubsequently heated at 110° C. for 12 hours. A deep colored monolithicsolid was obtained. After washing with water extensively, the solid waswash with ethanol for 24 hours in a Soxhlet extractor. The product wasdried under vacuum at 120° C. for 12 hours.

Example 3

PPN1 film fabrication procedure. Monomer 1 (90 mg) and methanesulfonicacid (1 mL) were added in a test tube. The mixture was heated up to 60°C. to become a homogenous solution. Several droplets of the solutionwere deposited onto a glass substrate. Two slides of micro cover glasswere placed at the edge of the substrate and another glass substrate wascovered on the solution drops. The glass substrates used in filmfabrication were pre-cleaned by CH₂Cl₂ and coated with a spray-coatedthin layer of PTFE releasing agent. Then the glass substrates wereheated at 110° C. for 24 h. deep colored film was obtained. The film wastransferred into a Soxhlet extractor and washed with ethanol for 24hours.

Example 4

M2¹, M3², and M5⁵ were synthesized according to procedure reported inthe literature [36-39], M1 and other starting reagents were purchasedfrom Aldrich and Alfa-Aesar and used as received without furtherpurification, Thermogravimetric analysis (TGA) data were collected onMettle-Toledo TGA-DSC-1 with heating rate 10° C./min from 30° C. to 900°C. under N₂ atmosphere. Solid state nuclear magnetic resonance (NMR)data were collected on Broker Advance-400 Solids NMR spectrometer. N₂adsorption data were collected on a Micrometrics ASAP 2020 surface areaand pore size analyzer.

Example 5 Spray Coating of PTFE on Glass Substrate

The glass substrate was first rinsed by acetone. Subsequently, a thinlayer of PTFE was spray-coated on substrate. After that, the substratewas placed in an oven at 315° C. for 1 h.

Example 6 Cost Estimation and Stability

The start materials and reagents for the production of diphenyl etherderived PPN (PPN2) are all inexpensive commodity industry chemicals:diphenyl ether ($3,000-5,000/ton), aluminum chloride ($1,000-2,000/ton),CH₃COCl ($2,000-3,000/ton), MSA ($1,000/ton). Moreover, the yield ofboth synthetic steps from diphenyl ether to PPN2 are high (over/80% andquantitative). Based on these data, it could be estimated that the costto synthesize PPN2 is much lower than current prevailing PPN productionmethods. For example, it is three orders of magnitude cheaper the costfor producing benchmark PPN6 (BET surface=6000 m²/g). Thiscost-efficiency is particular advantageous for industrial applicationsthat do not require ultrahigh porosity, e.g. filtration and sensing,PPNs prepared by our method show high thermal stability up to 400° C.,which is highly desired in industrial areas.

Example 7 Advantages of the Solution Precursor Method

In general, the processing of PPN into desired forms has beenchallenging because of the cross-linked and insoluble nature of PPN.This invention, however, enables solution-processing of the PPNprecursor into different forms and its in-situ reaction, affordingpossibilities to porous product formation and applications that are notpossible using conventional PPN synthesis. In addition, this methodmakes PPN much easier to process than other typical sp² carbonmaterials, such as carbon nanotubes. By casting the precursor solutionon different functional substrates followed by crosslinking, PPN filmcould be fabricated and used for filtration and separation purpose. Forexample, the free-standing film could be formed and transferred ontoother supports for different applications (FIG. 11a-c ). In addition,the PPN products could be shaped as what we design by filling thesolution of precursor into a mold. This solution method also allows forthe integration of additives to the PPN matrix. For example, theintroduction of fillers like graphene and carbon nanotube could enhancethe electronic and mechanical performances of the PPN compositematerials. The in-situ PPN formation also allows for an integratedsensor device composed of electronic active components and the PPN (FIG.12). Finally, this method is also promising to solve problems associatedwith defects and pinholes in porous membranes. The PPN precursorsolution filled in and the in-situ polymerization can be employed toafford a pinhole-free membrane.

Example 8 Industrial Application

It is believed that some of these particular porous polymer networks maybe useful in the industrial application of metal removal. FIG. 13 showsthe structure of two particular porous polymer networks. These polymernetworks may be synthesized in the methods previously described usingpreviously described monomers/compound type are

Example 9 Nanofiltratin Applications

The PPN films demonstrated excellent molecular filtration functions. Ina filtration process under positive pressure, the film allows permeationof solvent molecules and small solute molecules, while solute moleculeslarger than the pore size are rejected. For example, the pore sizes ofPPN1 film (made of 1,4-diacetyl benzene monomer) are mainly smaller than2 nm, thus suitable for nanofiltration of molecules over 600 g/mol.

In a standard nanofiltration setup, the free-standing PPN1 films weresealed by an aluminum foil tape, leaving the effective diameter of 1.8cm exposed to the solution. Carbon fiber paper was used as a marcoporoussupport. The nanofiltration tests were conducted using a Millipore'ssolvent resistant stirred cell at 5 bar (FIG. 14). In order to ensuredata reliability and reproducibility, target solution was filtrated atleast 20 h before sample collection, so that the completion ofadsorption and fouling of PPN films are achieved. Tested samples werecollected for 30 min. The concentration of feed solution and permeatesolution were calculated from the corresponding UV-vis light absorbance.

The PPN films demonstrated rejection >99% to solute molecules withmolecular weight equal to or higher than 624 g/mol, while the rejectionto smaller molecules such as Rhodamine B (480 g/mol) was as low as 9.4%(FIG. 16, FIG. 17, and FIG. 18). These results showed an outstandingselectivity of these PPN films against solutes of different sizes duringnanofiltration. This selectivity is attributed to the narrow pore sizedistribution of PPN1 film.

As a result of the permanent high porosity (BET surface over 800 m²/g),the permeance of PPN1 film is much better than commercial nanofiltrationmembranes. Compared to the market leading membrane DuraMem® 150 fromEvonik, PPN1 films demonstrated 10 times higher methanol permeance (5.0vs 0.48 L m⁻² ⁻¹bar⁻¹) [40], 20 times higher acetonitrile permeance(10.2 vs 0.47 L m⁻²h⁻¹bar⁻¹) [40], and 50 times higher tetrahydrofuranpermeance (5.2 vs 0.1 L m⁻²h⁻¹bar⁻)[41]. Permeance of PPN1 film is alsocompetitive comparing to the state-of-art nanofiltration membranesreported in literature. For example, the methanol permeance of PPN1 isin the same range with that of best reported cyclodextrin (5.8 Lm⁻²h⁻¹bar⁻¹)[42] and polyarylate (8.0 L m⁻²h⁻¹bar⁻¹)[43] nanofiltrationmembranes. The advantage of our PPN1 films is that they could reach suchhigh permeance at a 40 μm thickness so that the film is free-standing.In contrast, the high permeance competitors have to be at a fewnanometers thick to achieve similar performance, leading to much moredemanding fabrication conditions and much lower tolerance on defects.The present invention PPN1 films were processed by straightforwardcasting technique, feasible for large scale production. Moreover, PPNfilms show non-sensitive permeability to nonpolar, polar erotic, andpolar aprotic solvents. The permeance of solvents depends only on thesolvent viscosity (FIG. 19).

In one embodiment, said nanofiltration comprises heavy metal waterfiltration. In one embodiment, said heavy metal water filtrationcomprises water purification for pharmaceutical applications. In oneembodiment, said heavy metal water filtration comprises soilremediation. In one embodiment, said heavy metal water filtrationcomprises ground water remediation. In one embodiment, saidnanofiltration comprises size exclusion filtration. In one embodiment,said size exclusion filtration comprises chemical mixture separation. Inone embodiment, said chemical mixture separation comprises filtration ofheavy metals. In one embodiment, said chemical mixture separationcomprises dye exclusion.

Example 10 Carbon Fiber Paper/PPM Composite Membrane Fabrication

A piece of carbon fiber paper (CFP) was soaked in a solution of monomer1 MSA (90 mg/mL), which was then heated at 45° C. for 6 hours to afforda gel. The soaked CFP was then taken out and the gel on the surface ofCFP was wiped off. Subsequently, this soaked CFP was further heated at110° C. for 12 h to trigger the in-situ polymerization of PPN in the CFPmatrix. After the reaction was completed, the sample was washed by DMFand ethanol. It was then soaked again in the same monomer 1/MSA solutionand heated to 110° C. after 6 hours of pre-treatment. Such“soaking-heating-washing” cycles were performed for 4 times to reach ahigh loading of PPN in the CFP matrix. See FIG. 20, FIG. 21, and FIG. 22

Example 11 Potential Procedure for Other PPN/CFP Composite

Using the similar procedure described above in Example 10, composites ofCFP with any PPN claimed in this patent application can be processedthrough the “soaking-heating-washing” cycles, using a solution of thecorresponding diacetyl-functionalized monomer in MSA (80˜100 mg/mL). Forexample, the CFP was soaked in PPN precursor solution in MSA. Themixture was heated at 45° C. for 6 h when gel formed. The composite wasthen taken out and the gel on the surface was removed. Subsequently, thecomposite was heated at 110° C. for 12 h followed by washed with DMF andethanol. The procedure was repeated on composite for 3˜6 times to give ahigh loading of PPN.

Example 12 Morphology Study of PPN1/CFP

SEM (FEI Quanta 600 FE-SEM) was used to study morphology of PPN/CFP withvoltage of 20 kV and working distance of 11 mm. The surface of sampleswas coated with a 10-nm layer of Pt/Pd prior to the SEM.

The top view SEM of pristine CFP showed carbon fibers randomlyintersected with each other, leaving with lots of voids as large ashundreds micrometer. Through the voids, deeper carbon fibers could beseen. After loading with PPN, those hundreds-micrometer voids in CFPwere filled up with PPN. While the superficial carbon fiber can still beseen, deeper carbon fibers was blocked by PPN in the voids. Thecross-section view SEM of CFP/PPN showed the tight bond between PPN andcarbon fibers. The macroporous features of PPN was not observed incross-section view SEM of CFP.

See FIG. 23 and FIG. 24

Example 13 Thickness Control

The permeance of PPN filial can be further optimized by decreasing thethickness of the PPN film. The thickness of PPN can be controlled byconcentration of monomer solution as well as the thickness of thephysical spacer when processing. By tuning these conditions, the PPNfilm thickness varies from 40 μm to 150 μm.

Example 14 Functional Group Installation and Applications

Special functional group could be introduced by two methods: (1) usingmonomers containing functional groups so that these functional groupscan be carried over to the final PPN structure, or (2)post-polymerization modification of the PPN to install functionalgroups. Installation of functional groups will lead to applications inadsorption and membrane filtration.

1. Specific Applications for Adsorption:

-   -   a) Installing mercapto, or thioether groups onto the PPN        backbone enables the ability to capture heavy metals such as Hg,        Pb, Ag, and Cu etc. from water.    -   b) Installing nitrogen rich ligands, such as cyclam        (1,4,8,11-tetraazacyclotetradecane), into the PPN enables the        ability to capture Ni, Cr, Zn, etc. metal ions.    -   c) Installing supramolecular host functionalities, such as        cyclodextrin, calixarene to the PPN enables the ability to        capture organic small molecules.

2. Specific Applications for Membrane Filtration:

-   -   a) Installing ionic functional groups (such as sulfonate group,        ammonium, or imidazolium groups) can modulate the rejection        selectivity of the PPN film against solutes with different        charges during nanofiltration.

Installing inert groups into the PPN can control the pore size of thefilm so that the molecular weight cut off can be modulated. The smallerthe pore size is, the lower molecular weight cut off for thenanofiltration is.

Thus, specific compositions and methods of methanesulfonic acid mediatedsolvent free synthesis of conjugated porous polymer networks have beendisclosed. It should be apparent, however, to those skilled in the artthat many more modifications besides those already described arepossible without departing from the inventive concepts herein. Moreover,in interpreting the disclosure, all terms should be interpreted in thebroadest possible manner consistent with the context. In particular, theterms “comprises” and “comprising” should be interpreted as referring toelements, components, or steps in a non-exclusive manner, indicatingthat the referenced elements, components, or steps may be present, orutilized, or combined with other elements, components, or steps that arenot expressly referenced.

Although the invention has been described with reference to thesepreferred embodiments, other embodiments can achieve the same results.Variations and modifications of the present invention will be obvious tothose skilled in the art and it is intended to cover in the appendedclaims all such modifications and equivalents. The entire disclosures ofall applications, patents, and publications cited above, and of thecorresponding application are hereby incorporated by reference.

REFERENCES

1. Bétard, A. and Fischer, R. A. (2012) “Metal-Organic Framework ThinFilms: From Fundamentals to Applications,” Chem. Rev. 112(2), 1055-1083.

2. Song, Q. et al. (2016) “Porous Organic Cage Thin Films andMolecular-Sieving Membranes,” Adv. Mater: 28(13), 2629-2637.

3. Zhu, C. and Fang, L. (2014) “Mingling Electronic Chemical Sensorswith Supramolecular Host-Guest Chemistry,” Curr. Org. Chem. 18(15),1957-1964.

4. Bisbey, R. P. et al. (2016) “Two-Dimensional Covalent OrganicFramework Thin Films Grown in Flow,” Am. Chem. Soc. 138(36),11433-11436.

5. Knopfmacher, O. et al. (2014) “Highly Stable Organic PolymerField-Effect Transistor Sensor for Selective Detection in the MarineEnvironment,” Nat. Commun. 5, 2954.

6. Xu, et al. (2013) “Conjugated Microporous Polymers: Design, Synthesisand Application,” Chem. Soc. Rev 42(20), 8012-3031.

7. Yaghi, O. M. et al. (2003) “Reticular Synthesis and the Design of NewMaterials,” Nature 423(6941), 705-714.

8. Li, J.-R. et al. (2012) “Metal-Organic Frameworks for Separations,”Chem. Rev, 112(2), 869-932.

9. Waller, P. et al. (2015) “Chemistry of Covalent Organic Frameworks,”Acc. Chem. Res. 48(12), 3053-3063.

10. Feng, X. et al. (2012) “Covalent Organic Frameworks,” Chem. Soc.Rev. 41(18), 6010-6022.

11. Cooper, A. I. (2009) “Conjugated Microporous Polymers,” Adv. Mater21(12), 1291-1295.

12. Yuan, D. et al. (2011) “Highly Stable Porous Polymer Networks withExceptionally High Gas-Uptake Capacities,” Adv. Mater. 23(32),3723-3725.

13. Lu, W. et al. (2010) “Porous Polymer Networks: Synthesis, Porosity,and Applications in Gas Storage/Separation,” Chem. Mater. 22(21),5964-5972.

14. Sumida. K. et al. (2012) “Carbon Dioxide Capture in Metal-OrganicFrameworks,” Chem. Rev. 112(2), 724-781.

15. Lee, J. et al. (2009) “Metal-Organic Framework Materials asCatalysts,” Chem. Soc. Rev. 38(5), 1450-1459.

16. Yoon, M. et al. (2012) “Homochiral Metal-Organic Frameworks forAsymmetric Heterogeneous Catalysis,” Chem. Rev, 112(2), 1196-1231.

17. Li,. J.-R. et al. (2009) “Selective Gas Adsorption and Separation inMetal-Organic Frameworks,” Chem. Soc. Rev. 38(5), 1477-1504.

18. Weber, J. and Thomas, A. (2008) “Toward Stable Interfaces inConjugated Polymers: Microporous Poly(P-Phenylene) andPoly(Phenyleneethynylene) Based on a Spirobifluorene Building Block,” J.Am. Chem. Soc. 130(20), 6334-6335.

19. Chen, L. et al. (2010) “Light-Harvesting Conjugated MicroporousPolymers: Rapid and Highly Efficient Flow of Light Energy with a PorousPolyphenylene Framework as Antenna,”J. Am. Chem, Soc. 132(19),6742-6748.

20. Jiang, J.-X. et al. (2007) “Conjugated MicroporousPoly(Aryleneethynylene) Networks,” Angew. Chem. Int. Ed. 46(45),8574-8578.

21. Jiang, J.-X. et al. (2008) “Synthetic Control of the Pore Dimensionand Surface Area in Conjugated Microporous Polymer and CopolymerNetworks,” J. Am. Chem. Soc. 130(24), 7710-7720.

22. Xu, H. et al. (2015) “Stable, Crystalline, Pawns, Covalent OrganicFrameworks as a Platform for Chiral Organocatalysts,” Nature Chemistry7(11), 905-912.

23. Huang, L. et al. (2003) “Synthesis, Morphology Control, andProperties of Porous Metal-Organic Coordination Polymers,” MicroporousMesoporous Mater 58(2), 105-114.

24. Smith, M. B. and March, J. (2001) Advanced Organic Chemistry (5thEd.), Wiley Interscience, New York.

25. Elmorsy, S. S. et al. (1991) “The Direct Production of Tri- andHexa-Substituted Benzenes from Ketones under Mild Conditions,”Tetrahedron Lett., 32(33), 4175-4176.

26. Cherioux, F. and Guyard, L. (2001) “Synthesis and ElectrochemicalProperties of Novel 1,3,5-Tris(Oligothienyl)Benzenes: A New Generationof 3D Reticulating Agents,” Adv. Funet. Mater 11(4), 305-309.

27. Cao, X.-Y, et al. (2003) “Extended II-Conjugated Dendrimers Based onTruxene,” J. Am. Chem. Soc. 125(41), 12430-12431.

28. Rose, M. et al. (2011) “A New Route to Porous Monolithic OrganicFrameworks Via Cyclotrimerization,” J. Mater. Chem. 21(3), 711-716.

29. Zhao, Y.-C. et al. (2011) “Thionyl Chloride-Catalyzed Preparation ofMicroporous Organic Polymers through Aldol Condensation,” Macromolecules44(16), 6382-6388.

30. Wisser, F. M. et al. (2014) “Tailoring Pore Structure and Propertiesof Functionalized Porous Polymers by Cyclotrimerization,” Macromolecules47(13), 4210-4216.

31. Gernon, M. D. et al. (1999) “Environmental Benefits ofMethanesulfonic Acid. Comparative Properties and Advantages,” GreenChem. 1(3), 127-140.

32. Zou, Y et al. (2015) “Solution-Processable Core-ExtendedQuinacridone Derivatives with Intact Hydrogen Bonds,” Org. Lett 17(12),3146-3149.

33. Yuan, S. et al. (2010) “Microporous Polyphenylenes with Tunable PoreSize for Hydrogen Storage,” Chem. Commun. 46(25), 4547-4549.

34. Medina, D. D. et al. (2014) “Oriented Thin Films of aBenzodithiophene Covalent Organic Framework,” ACS Nano 8(4), 4042-4052.

35. Medina, D. D. et al. (2015) “Room Temperature Synthesis ofCovalent-Organic Framework Films through Vapor-Assisted Conversion,” J.Am. Chem. Soc. 137(3), 1016-1019.

36. Ray, J. K. et al. (2001) “Molecular Recognition: Studies on theSynthesis of Some Bis Thiophene Carboxamide Derivatives as DitopicReceptors for Long Chain Dicarboxylic Acids,” Tetrahedron 57(33),7213-7219.

37. Li, Y. and Zheng, Y. (2016) “Synthesis and Characterization of aFerrocene-Modified, Polyaniline-Like Conducting Polymer,” J. Appl.Polym, Sci, 133(13), n/a-n/a.

38. Stobe. C. et al. (2014) “Synthesis, Chiral Resolution, and AbsoluteConfiguration of C2-Symmetric, Chiral 9,9′-Spirobilluorenes,” Eur. J.Org. Chem. 2014(29), 6513-6518.

39. Hsiao, T.-S. et al. (2014) “Molecular Design for theHighly-Sensitive Piezochromic Fluorophores with Tri-Armed FrameworkContaining Triphenyl-Quinoline Moiety,” Dyes Pigm. 103, 161-167.

40. Karan, S. et al. (2015) “Sub-10 Nm Polyamide Nanofilms withUltrafast Solvent Transport for Molecular Separation,” Science348(6241), 1347.

41. Jimenez-Solomon, M. F. et al. (2012) “High Flux Membranes forOrganic Solvent Nanofiltration (Osn)—Interfacial Polymerization withSolvent Activation,” J. Membr. Sci. 423(Supplement C), 371-382.

42. Villalobos, L. F. et al. (2017) “Cyclodextrin Membranes:Cyclodextrin Films with Fast Solvent Transport and Shape-SelectivePermeability (Adv. Mater. 26/2017),” Adv. Mater. 29(26), 1606641.

43. Jimenez-Solomon, M. F. et al. (2016) “Polymer Nanofilms withEnhanced Microporosity by Interfacial Polymerization,” Nat. Mater 15(7),760-767.

We claim:
 1. A method for the preparation of porous polymer networkcomprising: (a) providing: (i) a plurality of compounds comprising atleast one acetyl group, said plurality of compounds comprising at leastone compound type, and (ii) an alkylsulfonic acid, and (b) treating saidcompounds under such conditions that reaction occurs to produce a porouspolymer network.
 2. The method of claim 1, wherein said alkylsulfonicacid is methanesulfonic acid.
 3. The method of claim 1, wherein saidmethod is lacking a toxic acid.
 4. The method of claim 1, wherein saidmethod is lacking an acid that decomposes at high temperatures.
 5. Themethod of claim 1, wherein said reaction occurs in open air conditions.6. The method of claim 1, wherein said method further providesadditional elements which become embedded within the porous polymernetwork after the reaction.
 7. The method of claim 6, wherein saidadditional elements comprise nanotubes.
 8. The method of claim 1,wherein said method includes more than one compound type.
 9. The methodof claim 1, wherein said method includes only one compound typecomprising at least one acetyl group.
 10. The method of claim 1, whereinsaid porous polymer network comprises a conjugated porous polymernetwork.
 11. The method of claim 1, wherein said reaction comprises analdol triple condensation.
 12. The method of claim 1, wherein saidcompound type is acetophenone.
 13. The method of claim 1, wherein saidcompound type is selected from the group consisting of:


14. The method of claim 1, wherein said compound type is selected fromthe group consisting of:


15. The method of claim 1, wherein said porous polymer network producedhas a specific surface area of greater than 1000 m²/g with a pore volumeof 0.40 cm³/g.
 16. The method of claim 1, wherein said compoundcomprising at least one acetyl group and said acid are in a homogenoussolution at or before step b).
 17. The method of claim 1, wherein saidconditions comprise heating.
 18. The method of claim 17, wherein saidcompounds and acid are reacted in a temperature range between 40-110° C.19. The method of claim 17, wherein said heating comprises heating to afirst temperature to produce a homogenous solution, followed by heatingto a second temperature to drive said reaction.
 20. The method of claim1, wherein said method further comprises step (c) wherein said acid isneutralized by aqueous base.
 21. The method of claim 20, wherein saidmethod further comprises step (d) wherein said porous polymer network isextracted with an organic solvent.
 22. The method of claim 21, whereinsaid method further comprises step (e) wherein said porous polymernetwork is purified by flash column chromatography.
 23. A method offabricating of a porous polymer network comprising: (a) providing: (i) afirst reactant comprising a plurality of compounds comprising at leastone acetyl group, said plurality of compounds comprising at least onecompound type, and (ii) a second reactant comprising an alkylsulfonicacid, and (b) creating a solution of said reactants, (c) casting saidsolution in a form, and (d) treating said solution under such conditionsso as to produce a porous polymer network.
 24. The method of claim 23,wherein the casting of step (c) comprises: i) deposition of portion ofsaid solution upon said first glass substrate, and ii) application ofsaid second glass substrate upon said first glass substrate such thatthe solution is between said substrates.
 25. The method of claim 23,wherein the treating of step (d) comprises: i) heating said substratesunder such conditions to produce a porous polymer network film.
 26. Themethod of claim 23, wherein said alkylsulfonic acid is methanesulfonicacid.
 27. The method of claim 23, wherein said method is lacking a toxicacid.
 28. The method of claim 23, wherein said method is lacking an acidthat decomposes at high temperatures.
 29. The method of claim 23,wherein said method further provides additional elements within saidform which become embedded within the porous polymer network after thereaction.
 30. The method of claim 29, wherein said additional elementscomprise nanotubes.
 31. The method of claim 23, wherein said methodincludes more than one compound type.
 32. The method of claim 23,wherein said method includes only one compound type comprising at leastone acetyl group.
 33. The method of claim 23, wherein said porouspolymer network comprises a conjugated porous polymer network.
 34. Themethod of claim 23, wherein said reaction comprises an aldol triplecondensation.
 35. The method of claim 23, wherein said compound type isacetophenone.
 36. The method of claim 23, wherein said compound type isselected from the group consisting of:


37. The method of claim 23, wherein said compound type is selected fromthe group consisting of:


38. The method of claim 23, wherein said porous polymer network producedhas a specific surface area of greater than 1000 m²/g with a pore volumeof 0.40 cm³/g.
 39. The method of claim 26, wherein creating a solutionat step b) comprises creating a homogenous solution of at least onecompound type and methanesulfonic acid.
 40. The method of claim 23,wherein said conditions of step d) comprise heating.
 41. The method ofclaim 40, wherein said compounds and acid are reacted in a temperaturerange between 40-110° C.
 42. The method of claim 40, wherein saidheating comprises heating to a first temperature to produce a homogenoussolution, followed by heating to a second temperature to drive saidreaction.
 43. The method of claim 23, wherein said method furthercomprises step (e) wherein said acid is neutralized by aqueous base. 44.The method of claim 23, wherein said reaction occurs in open airconditions.
 45. The method of claim 23, wherein said porous polymernetwork produced has a basic structure selected from the groupconsisting of


46. The method of claim 23, wherein said porous polymer networkcomprises a metal absorbing porous polymer network.
 47. A mixturecomprising a solution of an alkylsulfonic acid and at least one compoundtype comprising one or more acetyl groups.
 48. The mixture of claim 47,wherein said solution is in a cast or mold.
 49. The mixture of claim 47,wherein said alkylsulfonic acid is methanesulfonic acid.
 50. The mixtureof claim 47, wherein said compound type is acetophenone.
 51. Acomposition comprising a porous polymer network having a basic structureselected from the group consisting of


52. The composition of claim 51, wherein said porous polymer networkcomprises a metal absorbing porous polymer network.